LG Motorsports G5X1 Camshaft - Get on the Stick

A New Camshaft From LG Motorsports Wakes Up Our C6 Project Car

Last month, I showed you the installation and testing of LG Motorsports' Pro Long Tube headers and a Stainless Works 3-inch exhaust system. These two components combined to free up nearly 30 horsepower and 30 lb-ft of torque at the rear wheels of our C6 project car, the Daytona 600. While that was a great start, I wanted more. And LGM had just the thing.

When performing a cam swap on an LS engine, most people choose to install ported stock or aftermarket cylinder heads at the same time. This is a logical plan, as the two components really need to complement each other for optimum performance. I had initially planned to go this route as well, but a couple of factors convinced me to take a more staged approach with D6C.

Truth be told, head availability was the largest factor in this decision. We all know that the market has an incredible number of LS cylinder heads available. So why not use one of them? Well, it just so happens that my favorite cylinder-head manufacturer is in the midst of developing an LS2-specific head to augment its existing, small-bore LS1 offerings. Intrigued by the possibility of breaking new ground, I decided that the large-chamber head for the large-bore LS2 might be just the ticket and definitely worth waiting for.

When I complained about this apparent setback to Louis Gigliotti, Jr., he had a completely different spin. "Don't sweat it-this is a good thing!" he assured me. "I've got a perfect little cam that is ideal for a stock LS2. It's emissions-friendly, makes huge torque, and is completely docile in traffic." Ever the cynic, I told him I was not interested in some limp-wristed smogger cam with an idle like a sewing machine. Louis assured me that I would be duly impressed with the idle as well.

Louis' advice was spot on. The LG Motorsports G5X1 cam does, indeed, seem to be the ideal cam for a stock LS2. There was a time, not too many years ago, that its 228/232-degree duration would have been considered pretty big for an LS engine. But in these days of 250-plus-degree duration cams in stock-displacement mills, the X1 is actually pretty conservative. With lift numbers of 0.588/0.574-inches, it is easy on the valvetrain, too.

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The dyno sheet tells the tale: D6C picked up 45 rwhp and 30 rwtq over the previous installation of the headers and exhaust. That puts the running total at 74 rwhp and 58 rwtq over our baseline.

So what's it like? Push the button to start the car (that still doesn't seem right), and it fires immediately, then settles into a slightly staccato rhythm at 900 rpm. And yes, Virginia, there is a pleasing lope-perfect for turning heads at the local cruise-in. Engage the clutch and roll out into traffic; you'll feel the additional torque instantly. The X1 makes a ton of grunt down low and on through the midrange, while enhancing the LS2's trademark top-end pull. When you drop the hammer, it's a whole new beast. This is no peaky, race-spec stick that only makes power above 5,000 rpm. It is totally tractable and would even work great in a daily driver, assuming you don't mind the extra attention your Corvette garners with its aggressive new sound. In short, the X1's a winner.

While a cam swap seems like an intimidating project, it really isn't beyond the ability of most DIYers, especially on an LS car. As with most things, a little patience and a lot of attention to detail will see you through. Included here are some of the highlights of D6C's cam swap. You're sure to find some useful tidbits, should you decide to tackle your own install.

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The dyno sheet tells the tale: D6C picked up 45 rwhp and 30 rwtq over the previous installation of the headers and exhaust. That puts the running total at 74 rwhp and 58 rwtq over our baseline.

Before you attack the cam swap, you'll need to remove the rocker arms and pushrods. This will allow the cam to be rotated, moving the lifters up into their retainers and permitting cam extraction. Start with the valve covers, then remove the bolts securing the rocker-arm base. The rockers and base can then be removed as one assembly, followed by the pushrods.

Removing the alternator will free up a lot of room on the driver's side, making life a bit easier.

You can now turn your attention to the front of the engine. Begin by removing the induction system. Here are the Vararam and the MAF on their way out.

In order for the cam to be removed, the radiator, radiator hoses, and A/C condenser need to be moved out of the way.

As D6C is a Z51-optioned car, it is equipped with an external power-steering cooler, as well as transmission and engine-oil coolers that are internal to the radiator. The engine-oil cooler lines need to be disconnected, allowing the oil to drain. We'll get to the PS and trans coolers in a few minutes.

Remove the sway-bar bushings and allow the bar to hang from the end links. Here, the tie rods have already been disconnected in preparation for removal of the steering rack. All of this is done in an effort to gain the necessary space for fan removal and to improve overall access to the front of the engine.

Now it's time for the power-steering cooler to come out. This would be a good time to disconnect the trans cooler lines as well.

Remove the bolts fastening the fan-shroud assembly to the radiator and then take out the shroud. Don't forget to disconnect the fan harness.

The steering rack should be removed next.

The next component requiring removal is the crank pulley. Be forewarned: You're not going to break its bolt loose with your 31/48-inch ratchet. For this, you're going to need the big artillery. With the bolt out, you'll need a three-arm puller to remove the pulley from the crank snout.

Now the water pump should be removed and set aside.

This is what you'll see once you've removed the timing cover. The component in the center of the photo (with the seven black bolts) is the oil pump. It need not be removed for a cam swap.

Reinstall the old crank-pulley bolt in the crankshaft snout. Turn the engine over several revolutions in order to seat the lifters in their retainers. This allows you to remove the cam without first taking out the lifters.

The three bolts retaining the cam sprocket can now be removed. GM endowed the LS2 with a quality timing set, so unless you are dealing with a high-mileage engine, there is little reason to replace it.

Four bolts secure the cam retainer. Remove the retainer and set it aside.

Now's the time to reposition the radiator and condenser. Note that all of the A/C lines were left intact, preserving the R134a coolant charge.

At long last, you can now remove the camshaft. Do this carefully to avoid chipping a lobe and potentially depositing metal into your engine!

Prior to installation, the new cam's bearing journals should be coated liberally with assembly lube. LG Motorsports recommends Redline lubricants, as their full-synthetic formulas provide unsurpassed lubrication and protection. Since all LS engines employ roller lifters, assembly lube is not needed on the cam lobes.

With the cam safely in its bore and the retainer back in place, you can begin re-assembly by returning the radiator to its proper location. This will make work on the front of the engine a little easier.

The cam-sprocket bolts can be reused, but a dose of Loc-Tite should be added prior to installation. Torque the bolts to 18 lb-ft. Consult your factory service manual for torque specs on everything else you've taken apart.

LG Motorsports recommended installing an underdrive crank pulley on D6C. We used Auto Specialties' unit, which reduces accessory speed by 25 percent, meaning less parasitic power loss for your engine. Always use a new crank pulley bolt!

You can now complete front-end reassembly, following the order in which parts were removed. Remember to refill all fluid systems.

Next, it's time to tackle the valvetrain. LG Motorsports uses Comp Cams components, including these 918 springs, hardened seats, and titanium spring retainers. The use of titanium means less weight for the spring to contend with, reducing the chance of valve float and lengthening service life. Take this opportunity to install new seals as well.

Once all the springs have been swapped, you can move on to the pushrods. Comp Cams once again supplied the hardware, in the form of its chromoly 7955 units. As the laser etching reads, these feature the stock (7.400-inch) length and sturdy, 0.080-inch-wall construction.

Reinstall the rocker-arm assemblies and torque to spec (22 lb-ft), then button up the engine with the valve covers. Once the alternator is back in place, it's time to double-check all wiring and hose connections and verify that all fluids are topped up. Now you're ready to fire it up!

As with most cams worth installing, the X1 benefits greatly from a PCM re-flash. Tuning the computer helps maintain the optimum air-fuel ratio through the engine's operating range. The rev limiter and idle rpm should also be raised slightly (to 6,700 rpm and 900 rpm, respectively, in our case). Our tune was performed with the car strapped to the Dynojet and the air-fuel ratio monitored with a wide-band oxygen sensor.